The present invention relates to a web-processing machine and to a method for open- or closed-loop control thereof. A variety of web-processing machines are known from the existing art, for example printing presses, packaging machines, film stretching machines, or machines for textile treatment. It is known in this context that such machines often comprise a plurality of transport rollers that transport the material to be treated. These rollers are usually equipped with controlled drive systems, and the drive systems in some cases take into account tensions of the material to be processed.
More specifically, web tension control systems or register control systems that proceed, in terms of their controller structure or controller parameter design or parameter adaptation, from a speed-independent modulus of elasticity (hereinafter e-modulus) of the material web, are known. This assumption of a speed-independent modulus of elasticity results in some cases, however, in less than optimal controller parameterizations. DE 10 2005 056 802 A1 discloses a closed-loop control system for the web tension of a material web. In this, control loop parameters of a web tension controller are determined in accordance with a characteristic curve predefinable as a function and/or at multiple support points.
Previously known web tension control systems or register control systems assume that a linear relationship exists between web tension and web elongation.